Democrats in the House of Representatives are demanding to know how much House Speaker John Boehner’s threatened lawsuit against President Barack Obama will cost and where the money will come from.

Four Democrats on the House Rules Committee fired off a letter to committee Chair Pete Sessions, R-Texas, Thursday inquiring about the price tag and where House Republicans will get the money to pay for what would likely be millions of dollars in legal fees for outside counsel.

‘The American people have endured enough waste from this House majority and we are demanding an estimate so that members of Congress and the American public will know the true cost of the House’s petty partisan lawsuit against the president,’ Rep. Louise Slaughter, D-N.Y., the rules committee’s ranking Democrat said. ‘Responsible members of this body have an obligation to ensure taxpayer money is not turned into a slush fund for high-priced outside lawyers with connections to Republican lawmakers.’

Boehner, R-Ohio, recently unveiled a resolution outlining what he believes is unconstitutional executive overreach by Obama for delaying implementation of the so-called employer mandate provision of the Affordable Care Act., a 2010 law the congressional Republicans have been aggressively trying to kill.

House Republican officials haven’t given an estimate on how much a lawsuit would cost. The resolution authorizes hiring outside lawyers, something Republican lawmakers did when they sought to uphold the Defense of Marriage Act before the Supreme Court. As of last year, the House authorized up to $3 million for outside legal help on the act.